Magnetic separator



J. P. BETHKE.

MAGNETIC SEPARATOR.

APPLICATION FILED NOV. 5. 19|?.

1,369,516. Patented Feb.22,1921.

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i257. z. 22 1,12 151i rWITNESSES- INvENToR ioni@BETIIKETOnMgiwAUKEE, WISCONSIN, ASSIGNO'R To MAGNETIC MANUFAC- TURING COMPANY, OF MrnwnuxEELLLLSQNSNLCORPORATION OF WISCONSIN.

MAGNETIC sErAizA'ron.

Specification of Letters Patent.

Application led November 5, 1917. Serial 110,200,354.

To all whom may concern.'

Be it known that I, JOHN P. Barnim, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful lmprovements in Magnetic Separators, 'of which the following isa full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to certain new and useful improvements in magnetic pulleys, and particularly such magnetic pulleys as are used in magnetic separators.

'The'objects'ofmy inventionare to produce a'magnetic pulley, which will have a maximum efficiency or separating capacity for a given expenditure of electrical energy; which will vloe of minimum bulk and weight for a given separating capacity, and which can beeconomically produced.

A magnetic pulley should be capable of developing, for a given expenditure of eleotrical energy, a maximum flux through the space about the poles, and a feature ofl importance is-to have this magnetici-lux increase in density at a Ilapid rate near thev pole pieces whereby the portative force of the ma netic pulley is greatly increased. To this en the poles of the magnetic pulley of my invention are formed to afford an ex# treme convergence o/ffthexlipesmfiorcexof warfdthc/polef/ces, the vfaces of the poles f/bgng adapted to this object.

' lt is desirable to have the pole pieces constructed so that they become fairly saturated so as to afford 'a high permeability for the metal of the magnetic pulley when separating magnetic materials from those thatv are non-magnetic.

It is also very desirable that a magnetic pulley should be so. contoured as to expose a considerable surface area for heat radiation, thereby making it possible to utilize a larger amperage vthan can be delivered through the windings in a pulley having less heat radiating surface. v

To secure these and other desirable ad# vantages, I provide a magnetic pulleyv inv which the pole pieces are arranged ,so that the magnetic flux set up by the magnets will converge rapidly in the region of the pole pieces, and that they will come to great magnetic density when supplied by magnetic material which may act as a keeper.

I also provide openings in the magnetic pulley for supplying air to the interior thereof, and means for causing the air to circulate freely through the openings.

-Referring to the drawings Figure l -is a side elevation o f a magnetic pulley separator, .comprising my invention.`

F1g. 2 is a longitudinal sectional elevation through the magnetic pulley, taken at line 2--2 of Fig. 1.

Fig. 3 is a fractional sectional View taken on line 3 3 of Fig. 1, and illustrating the fan-like arms at the ends of the magnetic pulley.

A magnetic Separator embodyingl my invention and shown in Fig. 1 has at its discharge end a magnetic pulley 1, and at lthe other end Aa plain or non-magnetic pulley 5. The material to be separated is fed through a hopper 6, or other suitable means, onto belt 7 which belt, moving in the direction of the arrows as indicated in Fig. 1, causes the material to pass over the magnetic pulley 4, the non-magnetic material dropping downward,- and themagnetic substances being-attracted and held tightly to the face of the belt, as long as the belt is in contact with the pulley, whereby these magnetic or magnetizable materials are carried under-I neatlr'rthe pulley, and b eyond a vertical plane through the pulley on the return side. The belt then mechanically conveys such Patented Feb. 22, 1921.

material out of proximity to the pulley, and

away from the magnetic field, the material being eventually allowed to drop at a substantial distance from the nonvmagnetic `material which either drops vertically from the downwardly moving side of the pulley, at a tangent to its surface, or -is thrown rearwardly from the vertical path by ,centrifugal force.

The magnetic pulley 4 comprises a number of sections of magnetic or magnetizable material, and each section 8 preferably has the general form of a spool, providedvwith loo a head at each end thereof in the form of an annular flange having a conical inner surface. These spool heads or ianges are .respectively marked 9 and 10 in the draw-. ing. Their Outer margins are cylindrical,

but are narrow, since the end faces of the the magnetic flux at their relatively narrow peripheral margins with dovetailed grooves 11 extending around their rims, for the purpose of holding the non-magnetic shields 12 tightly in place on the magnetic pulley. The sections 8 are provided on their inner edges with offsets 13, so that when they are 'mounted together they may be drawn up tightly together, and actas one drum. The bolts 14 extend through the magnetic pulley from end to end, and are used for drawing the sections together and holding them, with the non-magnetic shields 12 tightly in place.

The spaces thus formed between the flanges 9 and 10, are arranged to contain the energizing coils 15.4 These coils are thoroughly insulated in' any well known manner, and are protected against external injury by means of the non-magnetic shields 12, which extend around the entire pulley. The c oils are wound in separate units on the sections 8, and so connected' together through the ducts 16 and 17 that when energized alterlnate magnetic poles are produced as indi-V cated in Fig. 2. The end sections of the magnetic pulleys 8a and 8" are provided with hubs 18 for mounting on the shaft 19. The radial arms 2O are fan-,like blades, Varranged to cause a circulation of air through the open interior 21, of the magnetic pulley when the same is rotated in operation, thereby dissipating the heat which rises inthe windings, and is conveyed through the metal of the sec'- tions 8- to the inside surface ofthe pulley. The inside surface of the magnetic pulley may be ribbed to further increase the radiatingcapacity thereof. The ends of the magnetic pulley are provided with non-magnetic flange rings 22. The shaft 19 is supplied with a drive pulleyy 23 for rotating the magnetic pulley, and ducts 24 are provided 1n the shaft for containing the lead wires whichl extend from the collector ring 25 to the coils 15, and serve to supply electric current to the coils for energizing the same.

When the pole pieces are constructed as hereinbefore shown and described, proper energization of the exciting coils will afford great magnetic strength to the pole pieces when separatin magnetic from nonmagnetic materials. he pole pieces de.- creasing in cross-sectional area toward their .vperipheries, cause the concentration of magnetic flux in that direction, as above explained, thereby producing a magnet of high intensity. It will be lreadily understood f from an inspection of the drawings that while the coils 15 are protected on all sides the walls of metal between the coils and the interior of the magnetic pulley are comparathe tively thin'and heat within may be readily dissipated. By this means it is possiblel to Work the windingsafely at a much higher current density, thus further affording greater strength to the magnets than heretofore possiblef I do not wish to be limited to the precise construction` herein shown, but desire that my invention be construed as providing the means set forth in the appended claims whereby the rate of-convergencgwofthemgrapid and is greatly increased over that in magnetic pulleys of the prior art, and whereby dissipation of heat is permitted from the interior of the pulley, thus allowing the cony tained energizing winding to be worked at a much greater' current density than heretofore possible, thereby materially increasing the separating capacity of the magnetic pulley. l

I claim for myinvention 1. The combination with 1a supporting shaft, of a magnetic pulley mounted thereon, and having an inner cylinder spaced from the periphery of the pulley and inclosing a longitudinally extending annular cavity between thepshaft and the peripheral portion netic lines of force toward the poles is very of the pulley, said cavity being open to the exterior at the respective ends of the pulley, a set of blades disposed in said cavity, and positioned to serve as fan blades to maintain circulation of air through said cavity, and` a set of pole pieces provided with energizing windings located between the inner cyl-v inder and the periphery of the pulley, and protected from dust by said inner cylinder.

2. A magnetic pulley in tubular form, in combination with an axial support, and a set of fan .blades supporting the peripheral portions of the pulley from the axial portions, and adapted 'to maintain an air current through the pu ey from one endtoV the other, said periphera portions of the pulley including a supporting cylinder and a set of pole pieces having windings mounted thereon, and provided With annular covers.

3. A magnetic pulley comprising a set of spools having integral end heads and disposed end to end, an energizing winding 'upon each spool between the heads of the said spool, peripheral bands of non-maignetizable material covering the windings between the respective ends of the spools, and means for binding the spools together.

l4f. A magnetic pulley comprising a set of spools disposed end to rend, and each provided with an energizing winding, peripheral bands of non-magnetizable material covcoil supporting spools, arranged end to end in .interlocking relatiornv to each other, and with the heads of the spools constituting pole pieces, coils mounted upon the respective spools, and provided with a covering of non-magnetizable material between the pole pieces. j 6. A magnetic pulley comprising a set of coil supporting spools, arranged end to end, and with the heads of the spools abutting and 4constituting pole pieces, coils mounted upon" the respective spools, and provided with a covering of non-magnetizable-material between the pole pieces, each of thespools having a head provided with an annular shoulder .with which the adjacent spool isadapted to interlock.

7. A magnetic pulley, including the combinationof a supporting shaft, pulley heads secured to the shaft, and provided with openings concentric with and near the shaft, and a set of spools, clamped end to end between said heads in interlocking relation to each other, and each carrying an energizing winding, said spools being of'sufficient diameter to provide an annular space between them and the shaft for air circulation, and the spool supports being adapted to promote air circulation through said space. v v8. A magnetic pulley comprising a supporting shaft, a set of pulley heads secured to the shaft, and a set of spools clamped between the pulley heads, each spool being in` tegrally headed at each end and provided with a winding, and having a peripheral surface in common with the surfaces of the other spools.

9. A magnetic pulley comprising a series of spools, each having spool heads at each end provided with 4conical inner surfaces, and having abutting end surfaces in radial planes, each of saidspool headshaving a peripheral belt receiving cylindrical surface, and all of said spools being rigidly secared together, end to end."

10. A magnetic pulley comprising a supporting shaft, a cylindrical barrel spaced therefrom, and provided with a series of energizing windings, annular flanges altermating in polarity, and projecting outwardly from said cylinder between the windings, and having converging side surfaces, said pole pieces being thereby adapted to concentrate the magnetic flux at the peripheries of said flanges, and along narrow annular 1 zones at the/periphery of the pulley.

11. A magnetic pulley comprising a shaft and a plurality of magnetic sections, adapted to be assembled thereon, an end flange on each of said sections adapted to interlock with the abutting end of the adjacent section, and spacer rings adapted to be held between the lianges of adjacent sections in assembled position.,

1 2.v A magnetic pulley composed of a plurallty of duplicate magnetic sections, adapted to be assembled to form the pulley, each section comprising a coil spool having a` large radial flange `and a small radial flange, and a spacer ring fitting over said small flange and engaging said large flange.

13. A magnetic pulley comprising a pluralit of axially alined separate magnetic `spoo s, each spool comprising a body portion having an integral flange at each end, and having an exciting coil wound uponsaid body portion between said flanges, and means for rotatably supporting the spools.

14. A magnetic pulley comprising a plurality of axially alined separate magnetic spools, each spool comprising a body portion having an integral flange at each end and having an exciting coil wound upon said body portion between said flanges, means ,for rotatably supporting vthe spools, and

means for accelerating the abstraction of heat from said pulley above the normal radiation from its exterior surfaces.

- 15. In a magnetic pulley, the combination with a shaft, of a plurality of'magnetic spool sections each having integral flanges at each end', certain of said spools being 1ndependently supported upon said shaft, each j of said spools havin a separate winding thereon, and rings bridging the end flanges of said spoolsand having circular periphries constituting a belt surface of said pui,-

16. In a magnetic pulley, the. combination with a shaft, of a plurality of independent magnetic spool sections supported thereby', each of said spool sections having end flanges and a winding thereon, and rings bridging the space between the end flanges of said spools, the rings having circular periplilerieslconstituting belt surfaces of said pu e 17.57A ventilated magnetic pulley comprising a plurality of hollow magneticspool i Ysections having flanges at each end and an exciting coil wound upon each spool section vand positioned'between said flanges, a shaft for rotatively carrying said spooll sections, and means for spacing the inner periphery of said spool sections from said shaft, where-l by ventilation is secured. j

18. A magnetic pulleycomprising a plurality of axially alined separate magnetic spools; each spool comprising a body por.- tion having an integral flange. at each end, said flanges having converging inner surfaces; lan exciting coil wound upon each spool between its end anges; means for r0- tatively supporting saidvspools; and means for accelerating the abstraction of heat from said pulley above the normal radiation from the exterlor surfaces; whereby increased current density within said coil is permitted and a free and unrestricted flux path is provided.

19. A magnetic pulley comprising a plurality of axially alined separate magnetic spoo s; each spool comprising 'a body portion having an integral flange at each end, said flanges having converging inner surfaces; and an exciting coil wound upon eacl1 spool between its end flanges; and means for rotatively supporting said spools; whereby a free and unrestricted flux path is provided.

20. A magnetic pulley having an interior cavity open to the exterior at a plurality of points, an energizing coil wound axially of said pulley, andmeans for insuring a positive circulation -of a cooling medium through said pulley, whereby said pulley mz be cooled both externally and interna y.

21. A magnetic pulley comprising a shaft, a spool supported therefrom and-arranged with an intervening space betweenl it and the shaft, and an air forcing wing adapted, when the pulley is rotated, to cause air circulation through said space.

'22. A magnetic pulley comprising a shaft, a series of concentric spools supported therefrom, eachA provided with an energizing winding and arranged with an annular cavbetween them and said shaft, and a set.

it ofy air cireulatin wings adapted-to be rotated with the pu ley and arranged to cause air circulationthrough said annular space. 23. The structure set forth in' claim 22, in which said air circulating wings comprise supports and spacing members for some of the spools adapted to support the series of spools at both ends from said shaft, 4

In testimony whereof I hereunto aiix my signature in the presence of two witnesses.

VJOHN P. BETHKE. Witnesses CHAs. STRASSMAN, RosE J. S'rRassMAN. 

